This invention relates generally to a beam clip used to secure load bearing beams to columns of upright frames in industrial storage rack systems, and, more particularly, to a beam clip having a self-locking feature to prevent the beams from becoming unintentionally disengaged from the columns.
Industrial type storage racks are typically constructed of interconnected beams and columns. In the usual case, the beam is connected to the columns of an upright frame via a connector that is welded or otherwise rigidly attached at each end of the beam. Typically, this connector is an angle shaped bent plate, often referred to as a clip, having a side flange welded to the end of the beam and a front flange which is provided with projections which attach the beam to the front face of the columns of the upright frame. The clip can be fitted against the column with the side flange adjacent the side wall of the column and the front flange against the front face of the column. In the usual case, the front face of the column has a linear array of regularly spaced apertures. The projections on the front flange of the clip can be configured to be inserted through and retained in the apertures in the front face of the column to hold the end of the beam thereagainst. Many of these devices attach to the side flange of the connector and engage into apertures in the side walls of the column.
Preferably, a locking device should be provided to restrain the front flange from becoming dislodged unintentionally from the front face of the column. Numerous locking devices have been disclosed for retaining the beam against the column for preventing unintentionally disengagement.
One such device employs a spring member latch mounted on the front flange of the clip. Such a spring member latch is illustrated in U.S. Pat. No. 5,624,045 to Hysmith et al., in FIGS. 12-13 labeled "Prior Art." The spring member has a flat portion which lies adjacent the front flange with one end attached to a first connector, which is typically a rivet, mounted on the front flange and an opposite end which extends towards a second rivet mounted on the flange. The rivets typically have a shank portion and an inner head portion larger than the shank. The opposite end has a latch portion projecting generally perpendicular to the flat body. The latch portion projects through a hole provided in the front flange near to the second connector. The latch is also long enough to project through one of the apertures when the clip is connected to the column. When the clip is installed on the column, each rivet projects through separate apertures in an upper region of each aperture. To lock the clip in place, the beam, and the clip, is moved downwards causing the rivets to then slide down into a narrow lower region of the apertures where the inner heads of the rivets are larger to be removed. When the rivets slide down into the narrow lower region the apertures the latch portion can then project through the upper region of an aperture common with one of the rivets. Thus, the locking portion prevents the beam from being lifted upwardly so long as it projects through the upper region of the aperture. To remove the clip, the locking portion must first be removed from the upper region of the aperture by flexing the flat body of the spring member. When the locking portion is thus removed, the clip can be moved upwards to permit the rivets to be removed back through the upper region of the apertures.
There can, however, be some disadvantages associated with such a spring member latch. For example, the spring member can be difficult to grasp and flex outward to dislocate the locking portion from the aperture when the beam is desired to be removed from the column. Additionally, for example, if the spring member is excessively flexed the spring can be bent or broken.
Another type of locking device, which is the subject of the Hysmith patent, is where the flanged clip has a central latching pin mounted to the front flange which is slideable along a vertical slot provided therein. The latching pin has an inner head, like the fixed connecting pins, or rivets, mounted on the front flange, which is configured to take advantage of the apertures in the columns that conventionally have a wide upper region and narrow lower region. The inner head is sufficiently small to be insertable in the wide upper portion of the aperture, but larger than the lower region thereof so that once installed the pin cannot be removed from the aperture. The latching pin is freely slideable along the vertical slot such that an upward movement of the beam would not result in an upper movement of the latching pin. If the beam were lifted upwardly such that the connecting pins might be dislodged from the apertures, the latching pin would nonetheless remain in the narrow portion of the aperture so that the beam could not be unintentionally dislodged from the column.
However, there can also be some disadvantages to using this kind of locking device. For example, since the latching member floats in the slot it cannot bear any weight. Thus, the amount of weight the beam can support is reduced by one third. Also, the weight of the floating pin actuates the latching function. But, since the weight of the pin itself is not significant, even a small amount of friction between the pin and the slot could cause the pin to stick and not fully drop down into a latched position. Consequently, even a small amount of rust, dirt, grease, etc. in the flange slot could conceivably prevent the pin from fully latching. Also, since these storage racks may remain assembled in warehouses for long periods of time, the latching pin can also become stuck in the vertical slot making it difficult to disconnect the beams from the columns. For example, the same rust, dirt, grease, etc. could accumulate between the latching pin and the flange slot which could cause the latching pin to stick in the latched position. Additionally, the accessible end of the latching pin is small and is not configured to be easily grasped. Thus, it could be difficult to manually move the latch or break it free if it were to become stuck.
Other types of self locking latches are known in the art which utilize spring biased locking mechanisms to retain the locking portion in a latched position. Most of these require a screw driver or other similar tool to manually flex the spring member to unlatch the beam clip. Others are designed to be grasped and pulled by hand. However, beam clips such as those described above, and herein, are about the size of a persons hand. The latches are a relatively small component and can be difficult to grasp even with bare hands. The situation is complicated even more when gloves are worn, as is common in the environment, typically warehouses and storage rooms, where storage racks such as described herein are frequently employed.
Thus, there is a need for a self-locking beam clip for preventing the beams from becoming unintentionally disengaged from the columns which is also designed to be quickly, easily and positively latched and unlatched. Such a beam clip preferably has a positive, self-locking engagement, and can be easily unlatched simply by pushing on the latch instead of having to pull on some small portion of the latch. The self locking latch also should not detract from the weight bearing capabilities of the beams and should be aesthetically appealing. The latch can also be configured to prevent damaged by over extension if unlatched in an improper manner.